Issue #2100329 by cosmicdreams: Use \Drupal instead of Drupal to make IDEs and static code analyse tools happy.

Issue #1614186 by RobLoach, tim.plunkett, msonnabaum, Crell, jhodgdon, Niklas Fiekas: Update coding standards for using 'native' PHP classes like stdClass in namespaced code.

- Patch #1506630 by Alan Evans, David_Rothstein: Fixed Namedspaced code throws and catches 'Exceptions' which don't exist (causing the DB settings form validation to break on install).